Human Genetics

Human Genetics

• Genetic Traits and Disorders
  • Genes that control human traits exhibit several patterns of inheritance
  • Gene patterns are the cause of genetic disorders
• Mutations
  • Can involve an entire chromosome oe a single DNA nucleotide
  • Germ-Cell Mutations
  • Somatic-Cell Mutations
  • Lethal Mutations - cause death. Often before birth
• Patterns of Inheritance
  • Traits are controlled by a single allele, like...
    1. Achondroplasia (Dominant)
    2. Cataracts (Dominant)
    3. Polydactyly (Dominant)
    4. Albinism (Recessive)
    5. Sickle-cell anemia (Recessive)
  • Multifactorial
    • Mutations in multiple genes
      • It makes them difficult to study and treat
  • Chromosomal Abnormality
    • Entire chromosomes or large segments of chromosomes are missing, duplicated, or otherwise altered
    • Nondisjunction is when chromosomes fail to seperate during cell division, resulting in an extra chromosome
      • One gamete gets an extra chromosome while the other gamete gets nothing
    • Frame Shift Mutation
      • Deletion
      • Insertion
    • Normal Mutation
      • Duplication
      • Translocation

• Down Syndrome = Extra 21st Chromosome

• X-linked Traits
  • Genes found on the X chromosome include:
    • Hemophilia
    • Muscular Dystrophy (Muscle weakness)
    • Colorblindness
• Pedigree
  • Shows the rate of how often a gene can be passed down to children
• Human Genome Project
  • Sequenced Human DNA

Link to a video that shows the birth of sickle-cell anemia, and the mutation that led to it:
http://www.pbs.org/wgbh/evolution/library/01/2/quicktime/l_012_02.html

Link to a GREAT animation regarding mutations during the Transcription phase:
http://highered.mcgraw-hill.com/sites/0072556781/student_view0/chapter11/animation_quiz_4.html